docs: def version_tuple(version):
      """Convert a version string or tuple to a tuple.
  
      Should be returned in the form: (major, minor, release).
      """
      if isinstance(version, str):
          return tuple(int(x) for x in version.split('.'))
      elif isinstance(version, tuple):
          return version
      else:
          raise ValueError("Invalid version: %s" % version)